bool
ImageOutput::copy_to_image_buffer (int xbegin, int xend, int ybegin, int yend,
int zbegin, int zend, TypeDesc format,
const void *data, stride_t xstride,
stride_t ystride, stride_t zstride,
void *image_buffer, TypeDesc buf_format)
{
const ImageSpec &spec (this->spec());
if (buf_format == TypeDesc::UNKNOWN)
buf_format = spec.format;
spec.auto_stride (xstride, ystride, zstride, format, spec.nchannels,
spec.width, spec.height);
stride_t buf_xstride = spec.nchannels * buf_format.size();
stride_t buf_ystride = buf_xstride * spec.width;
stride_t buf_zstride = buf_ystride * spec.height;
stride_t offset = (xbegin-spec.x)*buf_xstride
+ (ybegin-spec.y)*buf_ystride
+ (zbegin-spec.z)*buf_zstride;
int width = xend-xbegin, height = yend-ybegin, depth = zend-zbegin;
imagesize_t npixels = imagesize_t(width) * imagesize_t(height) * imagesize_t(depth);
// Add dither if requested -- requires making a temporary staging area
boost::scoped_array<float> ditherarea;
unsigned int dither = spec.get_int_attribute ("oiio:dither", 0);
if (dither && format.is_floating_point() &&
buf_format.basetype == TypeDesc::UINT8) {
stride_t pixelsize = spec.nchannels * sizeof(float);
ditherarea.reset (new float [pixelsize * npixels]);
OIIO::convert_image (spec.nchannels, width, height, depth,
data, format, xstride, ystride, zstride,
ditherarea.get(), TypeDesc::FLOAT,
pixelsize, pixelsize*width,
pixelsize*width*height);
data = ditherarea.get();
format = TypeDesc::FLOAT;
xstride = pixelsize;
ystride = xstride * width;
zstride = ystride * height;
float ditheramp = spec.get_float_attribute ("oiio:ditheramplitude", 1.0f/255.0f);
OIIO::add_dither (spec.nchannels, width, height, depth, (float *)data,
pixelsize, pixelsize*width, pixelsize*width*height,
ditheramp, spec.alpha_channel, spec.z_channel,
dither, 0, xbegin, ybegin, zbegin);
}
return OIIO::convert_image (spec.nchannels, width, height, depth,
data, format, xstride, ystride, zstride,
(char *)image_buffer + offset, buf_format,
buf_xstride, buf_ystride, buf_zstride);
}
